1. Field of the Invention
The invention relates to a spectroscope which produces multiple laser beams.
2. Description of the Prior Art
U.S. Pat. No. 6,327,090B1, entitled xe2x80x9cMultiple Laser Beam Generationxe2x80x9d illustrates a reflecting object 10 that has a plurality of reflecting surfaces, with the reflecting object made of a glass material. This reflecting object 10 is shown in FIG. 1 herein. Referring to FIG. 1, four protruding reflecting surfaces 11, 12, 13 and 14 are provided, with the angle between each reflecting surfaces 11, 12, 13 and 14 and a laser beam 20 being 45 degrees. A fifth reflecting surface 15 is positioned to allow the laser beam 20 to pass directly therethrough. As the laser beam 20 passes through the reflecting object 10, the laser beam 20 is divided into five branch laser beams 21, 22, 23, 24 and 25. Since the fifth reflecting surface 15 is perpendicular to the laser beam 20 (i.e., there is no any refraction angle between them), a further hole (not shown) can be provided for the laser beam 20 to pass through directly.
The reflecting object 10 in U.S. Pat. No. 6,327,090B1 is essentially a glass material positioned in a path where the laser beam 20 travels, so the laser beam 20 travels from a medium with low refraction index to another medium with high refraction index. Therefore each reflecting surface 11, 12, 13 and 14 must be coated with a reflective coating, otherwise there may little or no reflection of the incoming laser beam 20. For example, in such a situation, only about 4% of the laser beam 20 might be reflected, with the other 96% passing directly through the reflecting object 10. Since the laser beam 20 is intended to pass directly through the fifth reflecting surface 15, a reflective coating is not needed for the fifth reflecting surface 15. However, the reflecting object 10 in U.S. Pat. No. 6,327,090B1 still suffers from the following disadvantages:
1. Reflective coatings are needed for each reflecting surface 11, 12, 13 and 14, which increases the cost of the reflecting object 10.
2. The glass material that makes up the reflecting object 10 must be grinded precisely, which requires complicated manufacturing processes that do not allow for mass-production, thereby increasing manufacturing costs.
It is an objective of the present invention to provide a spectroscope that produces multiple laser beams without the need for any coatings on the reflective surfaces.
It is another objective of the present invention to provide a spectroscope that can be formed by injection molding or glass sintering.
It is another objective of the present invention to provide a spectroscope that can be mass-produced at lower manufacturing costs.
It is another objective of the present invention to provide a spectroscope that is capable of increasing or decreasing the number of laser beams generated.
In order to accomplish the objectives of the present invention, the present invention provides a spectroscope that has a body having a front surface, a rear surface, and a concavity provided in the rear surface. The concavity is defined by a plurality of angled reflective surfaces and an inner flat surface, with the inner flat surface being perpendicular to a longitudinal axis and parallel to the front surface. A laser beam directed at the front surface is divided into a plurality of branch laser beams, with one branch laser beam generated for each of the plurality of reflective surfaces and the inner flat surface.
Due to the fact that the laser beam is emitted from a medium having a high refraction index through a medium having a low refraction index, and an incident angle that is greater than a critical angle of total internal refraction, when the laser beam contacts the reflective surfaces of the concavity, a total internal reflection feature is provided, thereby omitting the need for coatings and allowing for the spectroscope to be mass-produced at low cost while maintaining a high degree of precision and manufacturing consistency.